Question

我想在按下ipython小部件按钮时递增计数器。我能够在下面的代码中使用global来解决这个问题，但有什么更好的方法呢？

import ipywidgets as widgets
from IPython.display import display

count = 0
w = widgets.Button(description='Click me')
w.on_click(plusone)
display(w)

def plusone(w):
    global count
    count +=1

Answer 1

使你的计数器成为一个对象并让你的回调将计数器对象作为参数。

class Counter:
   def __init__(self, initial=0):
      self.value = initial

   def increment(self, amount=1):
      self.value += amount
      return self.value

   def __iter__(self, sentinal=False):
      return iter(self.increment, sentinal)

然后你可以只传递这个对象的实例..

import ipywidgets as widgets
from functools import partial
from IPython.display import display

def button_callback(counter, w):
    counter.increment()    

counter = Counter()
w = widgets.Button(description='Click me')
w.on_click(partial(button_callback, counter))
display(w)

#... sometime later

if counter.value > SOME_AMOUNT:
    do_stuff()

使用ipython小部件增加计数器

1 个答案: